1. Field of the Invention
This invention relates to tamper evident devices and more particularly to the tamper evident devices at the juncture of interconnected sections of medical fluid conduits to provide an indication that the sections have or have not been disconnected and then reconnected.
2. Prior Art
Human body fluid drainage systems, such as urine collection systems, often include a catheter, such as a Foley catheter, having its distal end disposed in the bladder of a patient and its proximal end connected to a tube connector of a drainage tube which connects the catheter with a urine collection container or bag.
Such Foley catheters are often maintained in position in a hospitalized patient and connected to the drainage bag for substantial periods of time. To avoid patient infections, such components are sold in a sterile condition. However, since the components are usually packaged and sold separately, there is a danger of bacteria entering the urine drainage system upon assembly and connection of the catheter to the drainage tube for use, this bacteria could thereafter cause a urinary tract infection in the patient. To avoid the possibility of bacteria entering the system at the time of connection of the catheter tube and drainage tube, some manufacturers preconnect the catheter and drainage tube with the tube connector at the factory, sterilize the preconnected system, and package and sell the system in the assembled condition.
However, certain hospital requirements necessitate the disconnection and reconnection of the catheter and drainage tube of urine collection systems such as when a replacement bag is required or bladder irrigation is desired without the removal of the original catheter from the patient. Additionally, patients are sometimes motivated to disconnect the drainage bag and tube from the catheter without authorization for reasons of patient mobility, convenience, comfort or the like. It is, of course important to hospital personnel to know if the system has been tampered with or if disconnection and reconnection has occurred, whether or not such was for an authorized purpose. For example, when monitoring or measuring urine drainage, it is necessary to know if there has been a disconnection of the urine collection container from the catheter in order to have confidence in the determination of total volume or urine passed by the patient.
In order to provide an assured indication that the catheter has or has not been disconnected and reconnected, a tamper-evident seal has been suggested. For example, U.S. Pat. No. 4,194,509 to Pickering et al proposes a tamper-evident shrink wrap which seals the juncture of the catheter and drainage tube prior to sterilization. This heat shrinkable wrap of Pickering et al consists of a length of heat shrinkable adhesive tape and a circumferentially extending tear strip made of a shrinkable resin, for example, a polyolefin such as a polyethlene. In order to apply this wrap material, a heat source must be used to shrink the wrap around the connection between the tubes. This tends to complicate the overall manufacture and assembly of the preconnected system and also does not allow for the medical user to assemble the tamper-evident seal at the patient bedside. After the tamper-evident seal of Pickering et al is in position, it conceals the juncture of the tube connector and the drainage tube, thereby making it difficult to subsequently ascertain that a proper, fluid-tight engagement exists between these elements. In order to disconnect these elements for any purpose, a tear strip located on the heat shrink seal of Pickering et al must be located, gripped and tangentially pulled away from the seal to tear a portion of the wrap away from the tube connector. It is sometimes not readily apparent however from the smooth band of wrap remaining around the connector that the connection between the catheter and drainage tube has been compromised.